import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.io.PrintWriter;
import java.net.ServerSocket;
import java.net.Socket;
import java.util.Scanner;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;

public class TcpEchoServer {
    private ServerSocket serverSocket=null;
    public TcpEchoServer(int port) throws IOException {
        serverSocket=new ServerSocket(port);
    }
    public void start() throws IOException {
        System.out.println("启动服务器!");
        ExecutorService executorService= Executors.newCachedThreadPool();
        while(true){
            Socket cilentSocket=serverSocket.accept();
            executorService.submit(()->{
                try {
                    processConnection(cilentSocket) ;
                } catch (IOException e) {
                    e.printStackTrace();
                }
            });
        }
    }
    public void processConnection(Socket cilentSocket) throws IOException {
        System.out.printf("[%s:%d] 客户端上线!\n",cilentSocket.getInetAddress(),cilentSocket.getPort());
        try(InputStream inputStream=cilentSocket.getInputStream(); OutputStream outputStream=cilentSocket.getOutputStream()){
            Scanner scanner=new Scanner(inputStream);
            PrintWriter printWriter=new PrintWriter(outputStream);
            while(true){
                if(!scanner.hasNext()){
                    System.out.printf("[%s:%d] 客户端下线!\n",cilentSocket.getInetAddress(),cilentSocket.getPort());
                    break;
                }
                String request=scanner.next();
                String response=process(request);
                printWriter.println(response);
                printWriter.flush();
                System.out.printf("[%s:%d] req:%s resp:%s\n",cilentSocket.getInetAddress(),cilentSocket.getPort(),request,response);
            }

        } catch (IOException e) {
            e.printStackTrace();
        }finally {
            cilentSocket.close();
        }
    }
    public String process(String request){
        return request;
    }

    public static void main(String[] args) throws IOException {
        TcpEchoServer server=new TcpEchoServer(9090);
        server.start();
    }
}